Synapses are a fundamental unit of computation in the brain and vary widely in their structural and functional properties. Each synapse is a biochemically complex machine, comprised of hundreds of different proteins that vary in both identity and quantity across synapses. The functional significance for most of these differences in molecular composition are poorly understood. Our goal is to understand how molecular diversity at synapses gives rise to useful variation in synaptic physiology, and how this may reflect the specialization of synapses to perform specific useful computations in their respective circuits.
We ask these questions in the context of odor-driven behaviors in the vinegar fly Drosophila melanogaster. We use the fly because we can make targeted, in vivo whole-cell recordings from individual identified neurons corresponding to specific processing channels. This, together with its compact size and sophisticated genetic toolkit, makes the fly olfactory system a powerful experimental system for relating synaptic physiology to circuit function. Our approach is to use carefully designed odor stimuli in combination with genetic strategies to constrain olfactory behavior to depend on the activity at a small number of identified synapses. We use molecular genetics to selectively manipulate these synapses, measure the functional outcomes using in vivo two-photon imaging and electrophysiological recordings, and make direct comparisons of synaptic function with neural coding and behavior.
The Hong lab is a good fit for trainees with an interest in synapse biology, neural circuits, the genetic basis of behavior, and/or comparative neuroscience. For more information about our research, please click here.